Governing mechanism for mixed-pressure turbines.



M. B. CARROLL. GOVERNING MECHANISM r01; MIXED PRESSURE TURBINES.

APPLIOATIOF FILED JUNE 3, 1912.

Patented Jan. "7, 1913.

Witnesses:

UNITED STATES PATENT oFFIcE.

MORRIS B. CARROLL, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY,-.A CORPORATION OF NEW YORK.

GOVERNING MECHANISM FOR MIXED-PRESSURE TURBINES.

To all whom it may concern:

Be it known that I, Momns BL CARROLL, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Governing Mechanism for Mixed-Pressure Turbines, of which the following is a specification.

This invention relates to elastic fluid turbines, and especially to those which are driven by low pressure steam, with a proof the turbine-driven generator at its propervalue. A drop in the supply of low pressure st-eamdoes not result in a drop in speed of the turbine, because its alternator tends to run in synchronism with the others and will be driven by them as a motor if the turbine does not drive it. Hence the speed governor cannot retain control of the steam supply as it should, and some additional means must be furnished to produce a proper regulation of the machine. In my present invention, I make use of a flow-responsive device in the low pressure steam main, so connected to the valve mechanism of the turbine that when the supply of low pressure steam drops off and its flow dimin'ishes, this conditlon of things will affect the valve mechanism of the turbine in a manner to open one or more of the high pressure steam valves, even though the speed of the turbine'has n t, ianged.

The invention wi l" e better understood from the followingdetailed description and The turblne illustrated is of the horizontal type receiving live steam from a and'havin high pressure valve mec anism I operate by a ydraulic motor 2, whose pilot valve 3 is coupled-to a floating. lever ipe 18 Specification of Letters Patent.

Application filed June 3,

Patented Jan. 7,1913. 1912. Serial No. 701,142.

governor 5 while the other is attached to the piston rod 6 of the motor by a lever 7, forming a well-known follow-up device. Low pressure steam is supplied to the turbine through the main 8 which is controlled by a throttle valve operated by the rack.9 which forms a part of the motor-operated valve mechanism, as usual.

In the main 8, I preferably provide an enlargement 10 in which is located a float 11 consisting preferably of a disk, mounted on a stem 12 which is guided in a bridge 13 and extends up through a stuffing box let. The float might, however, be arranged in a cylin: drical pipe of uniform diameter. A lever 15 is pivotally attached to the upper end of this stem and fulcrumed at a point 16, its other end being connected by a link 17 to the system of levers connected to the pilot valve. An adjustable weight 15 may be mounted on the lever 15 to vary the effective action of the float. The float-11 responds to variflowing through the main 8, and by reason of its connections with the valve mechanism it will be seen that when the quantity of such steam falls off, the float will descend and the pilot valve will be actuated to cause its motor to open one or more high pressure valves and admit live steam to the turbine, to compensate for the lack .of low pressure steam. In this way the turbine will be enabled to carry its load even though the speed governor fails to actuate the pilot valve. Conversely, as soon as the supply of low pressure steam is increased, the oat will rise 4, one end of which is actuated by the speed ations in the quantity of low pressure steam I and tend to close the high pressure valves,

so as to prevent any undue overloading of the turbo-generator. This flow-responsive device is simple and effective, and operates quite independently bf the pressure of thesteam in the low pressure main, depending whollyupon the quantity of steam passing by it, so that it is sensitive and prompt in action. F i r In accordance with the provisions 'of the patent statutes, I h y". described the principle of operation of my invention, together with the a paratus WlllCh I now consider to .re resentt e best embodimentthereof; but I sire to have it understood that the apparatus shown is only illustrative, and that the n invention can be carried'out by other means.

\Vhat I claim as new and desire to secure by Letters Patent of the United States, is 1. Means for governing a mixed pressure turbine, comprising a speedresponsive device, a flow-responsive device, and valve mechanisrmfcontrolled by both of said devices independently.

2. Me'ans for governing a' mixed pressure turbine, clomprising valve mechanism for regulatin the admission of low pressure steam and high pressure steam to the turbine, a motor for actuating said mechanism, a.speed-respon'sive device controllin said motor, and a flow-responsive device In the low pressure main adapted to control said mot r independently of the speed-responsive device.

3. Means for goi' ern'ing, a mixed pressure turbine, comprising-valve mechanism for regulating the admission of low pressure steam and high pressure steam to the turbine, a motor for actuating said mechanism, a float in the low pressure main, and operative means whereby said float controls said motor.

4. Means for governing a mixed pressure turbine, comprising valve mechanism for admitting low pressure steam and high pressure steam to the turbine, a low pressure main having an enlargement, a float located in said enlargement, and operative connections whereby said float controls said valve mechanism.

In Witness whereof, I have hereunto set my hand this first day of June, 1912.

. MORRIS B. CARROLL.

Witnesses:

BENJAMIN B. HULL, HELEN Onrono.

Ctples o f this patent may be obtained for. five cents each, by addressing the Commissionero! Patents,

' Washington, D. G. 

